engleski

Morphological Changes of Lactic Acid Bacteria in the Presence of Aflatoxin B1 and Ochratoxin A

Mycotoxins are secondary products formed in the metabolic process of molds and can have carcinogenic, mutagenic, immunotoxic and teratogenic properties. Aflatoxins are well known and most toxic natural mycotoxins, produced by many species of Aspergillus fungi, mainly A. flavus and A. parasiticus. Aflatoxin B1 (AB1) is the most toxic compound from the group and is a common contaminant in a variety of foods including peanuts, corn, rice, wheat and other grains as well as animal feeds. AB1 is classified as group 1 carcinogen by IARC classification. Ochratoxin A (OTA) is a mycotoxin produced by several species of Aspergillus and Penicillium fungi. OTA is detected worldwide in various food and feed sources such as cereals, coffee, spices, cocoa and their processed products. Because of its hazard to human and animal health, OTA has received increased attention worldwide. IARC has classified OTA as a group 2B carcinogen. Lactic acid bacteria used in fermented dairy products as a starter culture may have a role in the reduction of aflatoxin in foods and nutrients. The aim of this study was to assess whether and how presence of AB1 and OTA affects the growth and morphological properties of selected lactic acid bacteria, Lactobacillus plantarum. L. plantarum was exposed to a toxin- containing medium during 72 hours at 37°C. In presence of both toxins, L. plantarum entered exponential phase of growth after 2 hours. Stationary phase, in presence of OTA started after 4 hours, and in presence of AB1 after 6 hours. In presence of both AB1 and OTA morphological characteristics of L. plantarum were changed. Length and width of the cells in media with toxins was reduced. The biggest difference in length for L. plantarum was observed after 72 hours and was 22% in AB1 containing medium and 16% in OTA containing medium. While biggest difference in width for L. plantarum was observed after 48 hours and was 15% in both toxin-containing mediums

mycotoxins ; lactic acid bacteria ; morphological properties

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